Peroxidised polyorganosiloxanes (POS), one of the methods for preparing them and their uses as bleaching agent in dental compositions

ABSTRACT

The invention concerns polyorganosiloxanes (POS) grafted with peroxide functions and functions stabilizing the latter. Said stabilized peroxidised POS are designed to form a novel oxidizing system useful as bleaching agents, for example or dental or detergent compositions. The invention aims at and succeeds in providing peroxygenated bleaching agents more stable and more efficient than those known in prior art. The inventive stabilized and peroxidised POS correspond for example to the formula (a). The invention also concerns a method for making said peroxidised POS, the precursors thereof and their uses as bleaching agents in dental compositions (toothpaste or detergent compositions).

This application is an application under 35 U.S.C. Section 371International Application Number PCT/FR99/02984 filed on Dec. 1, 1999.

The field of the invention is that of peroxide-comprising systems whichcan be applied in particular in bleaching, disinfecting, cleaning or theinitiation of polymerizations (for example radical polymerization) or ofepoxidation reactions. The oxidizing properties of these systems aremore particularly valued in bleaching applications, in particular dental(e.g. dentifrice) or detergent applications.

The peroxide-comprising systems targeted in the context of the presentaccount are functionalized polymers.

The present invention relates to peroxide-comprising polyorganosiloxanes(POS) and to one of their processes of preparation.

The invention also relates to silicone precursors of theseperoxide-comprising POSs.

Finally, the present invention comprises an application aspect whichcomprises the use of peroxide-comprising POSs according to the inventionas active ingredient in bleaching, disinfecting, cleaning and theinitiation of chemical reactions. More specifically, the invention istargeted at dental compositions, for example dentifrices, or detergentcompositions comprising peroxide-comprising POSs as bleaching agent.

The use is known of hydrogen peroxide H₂O₂ or its persalts (calciumperoxides, perborates, percarbonates) in the field of bleaching, inparticular dental bleaching. In the continuation of the present accountH₂O₂ will denote H₂O₂ as such or its persalts. The disadvantages ofhydrogen peroxide are not insignificant. Firstly, H₂O₂ has to beemployed at a high concentration to be effective. This point isparticularly annoying because of the aggressiveness of H₂O₂. Secondly,it is known that the bleaching action is related to the oxygen-donatingeffect. In point of fact, this effect is not the predominant effectwhich can be obtained with hydrogen peroxide. The latter behavesessentially as a promoter of deleterious free radicals which do notparticipate in the bleaching function and which instead would even havea tendency to interfere with it. Thirdly, hydrogen peroxide has thedisadvantage of being unstable.

There thus exists a clearly identified need for a substitute of hydrogenperoxide for these applications in the field of bleaching and inparticular of dental bleaching (dentifrices).

In attempting to solve the problem targeted above, U.S. Pat. No.5,698,326 has provided peracid compounds composed of an inorganicsupport formed of silica which carries peracid functionalities. Thesecompounds can be obtained by reacting silica substituted by asiloxylalkylamino residue with a trimellitic anhydride, the carboxylicfunctional group of the benzyl nucleus of which is subsequently oxidizedto convert it to a peracid functional group. This corresponds to thefollowing formula:

According to this patent, the grafting of the peracid functional groupto the inorganic support made of silica is sensible to make possiblestabilization of the peracid functional group. In reality, it turns outthat this stability might be further improved. In addition, there isreason to fear that these peroxide-comprising silicas are difficult todisperse in relatively viscous compositions, such as dentifrices.European patent application No. 796 874 relates to a process for thepreparation of polymers comprising peroxycarboxylic groups. Theseperoxycarboxylic polymers are more specificallyN-vinylpyrrolidone/maleic anhydride copolymers. Hydrogen peroxide, whichis reacted with this copolymer, makes it possible to convert carboxylsresulting from anhydride to peroxycarboxylic functional groups. Theperformance of these peroxycarboxylated copolymers in terms of bleachingwas not revealed by this patent application. Furthermore, it seems that,in the dental bleaching application, peroxycarboxylated copolymers lackselectivity with regard to teeth. In addition, problems of instabilitymay be feared for dental bleaching applications of these copolymers.

Patent application PCT WO 97/02 011 discloses dental oral compositionscomprising conventional ingredients, such as abrasives, binders,humectants, surfactants, sources of fluorine ions or other sweetenersand two other essential ingredients, namely, first, anaminoalkylsilicone, such as a polydimethylsiloxane comprising aminoalkylunits of the propylaminoethylamine type in the chains and at their ends,and, secondly, a polydimethylsiloxane comprising pendant groups ofpolyoxyethylene and/or polyoxypropylene type having a surfactant action.

No mention is made in this document of polyorganosiloxanesfunctionalized by peroxide units. This oral composition is presented ashaving improved antiplaque and antibacterial properties, whichcomplement an excellent cleaning performance. This oral composition canalso comprise bleaching agents belonging to the family of inorganicperacid salts (metal persulfates, perborates, percarbonates andperoxides).

These oral compositions are not satisfactory as regards stability,toxicity, selectivity with respect to teeth and effectiveness ofbleaching by oxidation.

In such a state of the art, one of the essential objects of theinventors was to develop a novel oxidizing system which can be used inparticular in bleaching, for example dental or detergent bleaching, indisinfection, in cleaning or in the initiation of chemical reactions,this oxidizing system of peroxide-comprising type having to be morestable and more effective than the known systems of the prior art.

Another essential object of the invention is to provide aperoxide-comprising bleaching system, in particular for dental bleachingapplications, which makes it possible to control the reactivity of theperoxide functional group, so as to limit as much as possible itsconversion to aggressive free radicals.

Another essential object of the invention is to provide aperoxide-comprising bleaching system which can be used in particular indental bleaching and which has a significantly improved stability onstorage.

Another essential object of the invention is to provide aperoxide-comprising bleaching system, applied in dental bleaching (oralcomposition for the treatment and maintenance of the teeth), having abetter selectivity with respect to teeth to be bleached.

Another essential object of the invention is to provide aperoxide-comprising oxidizing system capable of being used as a systemfor the controlled release of oxidizing peroxide functional groups,indeed even of free radicals which initiate chemical reactions.

Another essential object of the invention is to provide a process forthe production of the abovementioned peroxide-comprising oxidizingsystem which is simple to employ and economic.

Another essential object of the invention is to stipulate the use of theperoxide-comprising oxidizing system targeted above as bleaching agent,as disinfecting agent, as cleaning agent or as agent for the initiationof chemical reactions.

Another essential object of the invention is to provide a dentalcomposition possessing an effective, stable and selective bleachingagent.

Another essential object of the invention is to provide a detergentcomposition comprising an effective, stable and economic bleachingagent.

These objects, among others, are achieved by the present invention,which relates to novel polyorganosiloxanes (POSs) comprising siloxaneunits of following formula (I): $\begin{matrix}{R_{a}E_{b}G_{c}{SiO}_{\frac{4 - {({a + b + c})}}{2}}} & (I)\end{matrix}$

-   -   in which        -   a+b+c=0 to 3        -   a, b, c=0 to 3        -   R corresponds to one or more identical or different            radicals, R being chosen from monovalent hydrocarbonaceous            groups, preferably from linear, branched and/or cyclic            alkyls and/or aryls, and more preferably still from linear            or branched C₁-C₄ alkyls and phenyl, xylyl and tolyl groups;        -   E corresponds to one or more monovalent functional            substituents, which are identical to or different from one            another, carrying one or more peroxo(—O—O—) functional            groups Fpo and each optionally comprising one or more            Fpo-stabilizing functional groups Fstab which are identical            to or different from one another and are chosen from            functional groups capable of bonding via weak bonds with Fpo            functional groups;        -   G corresponds to one or more functional substituents,            identical to or different from one another, each comprising            one or more Fpo-stabilizing functional groups Fstab which            are identical to or different from one another and are            chosen from functional groups capable of bonding via weak            bonds with the Fpo functional groups;    -   with the conditions according to which:        -   (i). the concentration of [Fpo] functional groups, expressed            by the ratio            $\frac{{Fpo}\quad{number}}{{Total}\quad{number}\quad{of}\quad{silicon}\quad{atoms}\quad{in}\quad{the}\quad{POS}}$        -    is defined as follows:

Δ 0 < [Fpo] Δ preferably 0.01 ≦ [Fpo] ≦ 1.0 Δ and more preferably still0.1 ≦ [Fpo] ≦ 0.6,

-   -   -   (ii). the concentration as mol % of T siloxane units            (a+b+c=1) and/or Q siloxane units (a+b+c=0) is defined as            follows:

Δ 0 ≦ [T and/or Q] ≦ 20 Δ preferably 0 ≦ [T and/or Q] ≦ 10 Δ and morepreferably still 0 ≦ [T and/or Q] ≦ 8.

These novel peroxide-comprising POSs make it possible to stabilize theperoxo functional group and to control its oxidizing activity byrestraining its activity for the production of free radicals. Inaddition, their bleaching and selectivity properties with respect toteeth make them particularly appropriate and effective bleaching systemsfor oral dental compositions, such as dentifrices.

This is because these silicones, functionalized by peroxo Fpos, have aspecific affinity with respect to constituent materials of the teeth (inparticular hydroxyapatite), so that they are selected vectors capable ofconveying the chemical bleaching functional groups onto the teeth. It isobvious that this optimizes the effectiveness of said functional groups.It follows that it is possible to reduce the doses, which is entirelyfavorable to decreasing the aggressiveness of the bleaching agent.

Furthermore, these peroxide functionalized silicones are hydrophobic andthus have the advantage of protecting the Fpo functional groups fromwater, which is a major component in the instability of the Fpofunctional groups.

The novel peroxide-comprising polyorganosiloxanes comprising Fpofunctional groups can be linear and/or branched and/or crosslinkedpolymers according to the percentage by weight of DTQ siloxyl unitswhich they comprise. Preferably, the peroxide-comprising POSs accordingto the invention predominantly comprise D units (a+b+c=2) and morepreferably still are linear.

Advantageously, the E substituents of the siloxane units (I) areidentical to or different from one another are chosen from(cyclo)aliphatic and/or aromatic and/or heterocyclic hydrocarbonaceousgroups optionally comprising one or more heteroatoms, preferably O, N, Sor Si, it being possible for these groups optionally to be substituted.

In just as advantageous a way, Fpo is included:

-   -   either in an acyl peroxide:    -    with X corresponding to H, to R^(x), representing an aliphatic        and/or alicyclic and/or aromatic and/or heterocyclic monovalent        hydrocarbonaceous radical, that is to say comprising, inter        alia, hydrogen and carbon atoms, optionally comprising one or        more heteroatoms (N, O, S and the like), it being possible for        this radical optionally to be substituted and it being possible        for R^(x) optionally to correspond to the same definition as        that given above for R in the formula (I), to a halogen,        preferably chlorine, or to a cation which makes it possible to        form a salt with the peroxo anion and which is preferably chosen        from the elements from columns Ia and IIA of the Periodic Table,    -   or in a peroxide residue comprising sulfur, phosphorus, silicon        or boron as oxygen carrier.

In other words, each peroxo functional group Fpo belongs to aperoxycarboxylic residue (acids, esters, halides, chlorides or salts) oralternatively a peroxide residue deriving from compounds comprisingsulfur, phosphorus, boron or silicon.

It can be, e.g.:

with X as above.

Mention may be made, as examples of X groups which are alkyls, of:methyl, ethyl, propyl or butyl.

Mention may be made, as examples of X groups which are cations, of: Na⁺,K⁺, Ca⁺⁺, Mg⁺⁺, and the like.

These peroxycarboxylic and noncarboxylic residues are connected to thesilicon of the POS chain via an aliphatic and/or alicyclic and/oraromatic and/or heterocyclic hydrocarbonaceous linking unit (that is tosay, comprising in particular carbon and hydrogen atoms) optionallycomprising one or more heteroatoms: N, O, S, and the like, optionally.

The assemblage comprising:

-   -   first, the peroxycarboxylic residue and/or the noncarboxylic        peroxy,    -   and, secondly, the linking unit, form the functional substituent        E.        In practice, the linking unit is, for example, of the        -alkyl-O-aryl (benzyl), -alkyl anhydride or -alkylimide-aryl        (benzyl) type, inter alia.

The advantageous stabilizing action of the Fstabs on the Fpos is apreferred characteristic of the functionalized POSs according to theinvention. In accordance with the latter, the Fstabs are located on the(pendant) functional substituents E and/or G. Without this beinglimiting, it is preferable for the Fstabs to be carried at least by theE group or groups, so as to be close to the Fpos to be stabilized. It isnot excluded to consider that the stabilizing effect of the Fstab isthus improved.

According to a preferred characteristic of the invention, the optionalstabilizing functional groups Fstab of the-E and/or G substituents ofthe formula (I) correspond to functional groups which can generate weakbonds (hydrogen bonds, e.g.) with Fpo and which are selected from thegroup consisting of:

-   -   functional units comprising nitrogen and/or oxygen and/or        fluorine and/or sulfur and/or phosphorus; carboxylic,        carboxylate, amide, imide, sulfonamide, hydroxyl, alkoxy, amine        or organofluorinated units being preferred;    -   cationic units, preferably those comprising one or more        quaternary ammoniums;    -   chelating units comprising one or more ether functional groups        and/or one or more amine functional groups, and/or phosphonate        and/or sulfonate chelating units.

The optional functional substituents G each comprise, in addition to theFstab group or groups, a linking unit which provides for the bondingwith a silicone chain. The linking units of the G substituents areidentical to or different from one another, which correspond to the samedefinition as that given above for the linking units of the Esubstituents.

The peroxide-comprising POSs forming the subject matter of the inventioncan be obtained:

-   -   either from chlorosilanes or from alkoxysilanes carrying the E        substituents, from chlorosilanes or from alkoxysilanes carrying        G substituents and from chlorosilanes or from alkoxysilanes        carrying the R substituents and/or hydrogen, by cohydrolysis,        polycondensation and polymerization of the hydrolyzed products        in the presence of cyclic diorganosiloxanes or redistribution in        the presence of polydiorganosiloxanes, and the like,    -   or from functionalized polydiorganosiloxanes by hydrosilylation        of hydrogenated polydiorganosiloxanes using complete or partial        olefinic precursors of the functional substituents E and G.

Within the meaning of the present account, the terms “complete orpartial olefinic precursors” correspond respectively:

-   -   to the case where the olefinic precursor is in the final form        and does not have to be subjected to other grafting operations        to result in the complete substituent which will be converted to        E or G after peroxidation (complete linking unit),    -   and to the case where the linking unit of the E or G        substituents is formed by several members placed end to end and        corresponding to intermediate synthetic forms, the olefinic        precursor constituting the first member, which is bonded, first,        to the silicone chain and, secondly, to the following member of        the linking unit.

Without this being limiting, preference is given, in accordance with theinvention, to peroxide-comprising POSs obtained by hydrosilylation ofolefinic precursors of E and G substituents. These hydrosilylationreactions can be carried out at a temperature of the order of 15 to 200°C., preferably of the order of 20 to 100° C., in the presence of acatalyst based on a metal from the platinum group. Mention may inparticular be made of the complex platinum derivatives disclosed in U.S.Pat. Nos. 3,715,334, 3,775,452, 3,814,730, 3,159,601 and 3,159,662. Theamounts of platinum catalysts employed are of the order of 1 to 300parts per million, expressed as metal, with respect to the reactionmedium. The olefinic precursors employed in these hydrosilylationsadvantageously do not comprise the Fpo peroxo functional groups buttheir non-peroxygenated forms F′po or any intermediate form of thelatter. It is preferable, in accordance with the invention, to providefor protection of the F′po precursor functional groups before thehydrosilylation. The POSS, grafted by hydrosilylation and carrying F′poprecursor functional groups, are optionally purified and then subjectedto oxidation, which makes possible the conversion of the F′po functionalgroups to Fpo functional groups.

According to a preferred embodiment of the invention, theperoxide-comprising POSs correspond to the formula (II) given below:R¹ ₃SIO—[SiR² ₂O ]_(m)—[SiR²EO]_(n)—[SiR²GO]₀—SiR³ ₃  (II)in which:

-   -   R^(I) and R³ independently representing a hydrogen, a hydroxyl        or a monovalent residue corresponding to the same definition as        that given for R above;    -   R² independently represent hydrogen, a hydroxyl or a monovalent        residue corresponding to the same definition as that given for R        above;

• 2 ≦ m + n + o ≦ 300 • preferably 3 ≦ m + n + o ≦ 50 • and morepreferably still 5 ≦ m + n + o ≦ 20 • 0 ≦ m ≦ 200 • preferably 1 ≦ m ≦100 • and more preferably still 1 ≦ m ≦ 10 • 0 ≦ n ≦ 50 • preferably 1 ≦n ≦ 10 • and more preferably still 2 ≦ n ≦ 4 • 0 ≦ o ≦ 50 • preferably 1≦ o ≦ 10 • and more preferably still 2 ≦ o ≦ 4.

More preferably still, the polyorganosiloxanes are characterized inthat:

-   -   R¹ and R³=C₁-C₃ alkyl, preferably —CH₃    -   R²=C₁-C₃ alkyl, preferably —CH₃    -   the functional substituent or substituents E simultaneously        comprise Fpo and Fstab functional groups.

In practice, without this being limiting, the functional substituents Eof the peroxide-comprising POSs each comprise a linking unit comprisingat least one bicarboxylated and/or benzoxylated and/or imide unit.

The case where the linking unit or units of the functional substituentor substituents E comprise at least one bicarboxylic unit corresponds toa preferred form of the invention in which the Fpo functional group isobtained from an anhydride which is converted, on the one hand, to Fpoand, on the other hand, to Fstab carboxylic functional group forstabilization of the neighboring Fpo.

The peroxide-comprising POSs according to the invention are stable andexhibit a high bleaching power.

According to another of its aspects, the present invention relates to aprocess for the preparation of the POSs as defined above. This processis characterized in that it consists essentially in oxidizing thepolysiloxane precursors of the targeted peroxide-comprising POSs. Thisoxidation is carried out using at least one oxidizing agent preferablychosen from the group consisting of:H₂O₂, O₂, O₃ and their mixtures.These -POS precursors are distinguished from the targetedperoxide-comprising POSs in that they comprise one or more F′pofunctional groups which are Fpo precursors and are composed:

-   -   of carboxyl residues:    -    with X′ corresponding to the same definition as that given for        X above;    -   and/or of acid anhydride residues:    -   and/or of aldehyde residues;    -   and/or of residues comprising sulfur, phosphorus, silicon or        boron.

These ester or anhydride functional groups of the -POS precursors can beterminal functional groups or functional groups which are includedwithin a ring.

As is indicated above, the polysiloxane precursors comprising F′pofunctional groups can be obtained by cohydrolysis of nonfunctionalizedchlorosilanes and alkoxysilanes and of chlorosilanes or alkoxysilanesfunctionalized by E and G substituents. The stage which follows thecohydrolysis can be a polycondensation and a polymerization of thehydrolysis products, in the presence of cyclic diorganosiloxanes, or astage of redistribution in the presence of polydiorganosiloxanes. Theseconventional syntheses of POS bycohydrolysis/polycondensation/polymerization or bycohydrolysis/redistribution are described in particular in W. Nell,“Chemistry and Technology of Silicones”, published by Academic Press,1968.

According to a preferred alternative, the starting materials used can behydrogenated polyorganosiloxanes which can be functionalized by reactingthem according to a hydrosilylation reaction (addition with olefinicprecursors of the E and G substituents). Reference will be made abovefor further details with regard to this hydrosilylation.

According to a preferred characteristic of the invention, the -POSprecursors which are subjected to oxidation to produce targetedperoxide-comprising POSs are selected from POSs carrying functionalsubstituents E:

-   -   anhydride substituents    -   and/or carboxyl substituents, preferably benzoyl substituents,    -   and/or aldehyde substituents, preferably benzaldehyde        substituents,    -   and/or sulfonyl substituents,    -   and/or phosphoryl substituents,    -   and/or siloxyl substituents,    -   and/or boroxide substituents.

More preferably still, the -POS precursors selected:

-   -   carry anhydride E groups, the oxidation being carried out using        H₂O₂ in the presence of a catalyst of strong base type,        preferably potassium hydroxide,    -   and/or carry carboxylic E groups, preferably benzoyl groups, the        oxidation being carried out using H₂O₂ in the presence of a        catalyst of strong acid type.

In accordance with the invention, it turned out to be particularlyadvantageous for the -POS precursors to exhibit, before the oxidationstage which makes possible the conversion of the F′po groups to Fpogroups, a molar purity ≧90%, preferably ≧95%.

In practice, this purification stage is carried out by any knownappropriate method, such as, for example, devolatilization or fractionalprecipitation from an organic solvent, such as methanol.

As regards more specifically the oxidation stage, it is seen that theoxidizing agents can be hydrogen peroxide, oxygen, ozone and theirmixtures.

In the case where the oxidizing agent is composed of hydrogen peroxide,the catalyst employed can be a strong base, for example an inorganicbase, such as KOH or NaOH, or alternatively a strong acid, for examplean inorganic acid, such as H₂SO₄, or an organic acid, such as MeSO₃H.The solvents employed in these scenarios are, for example, ethyl acetateor MeSO₃H.

When the oxidizing agent is oxygen, the use can be envisaged of acatalyst comprising CO²⁺.

In practice, this oxidation stage can take place at ambient temperatureand at ambient pressure.

Another subject matter of the present invention is the POS precursorscomprising a F′po precursor functional group as defined above. Thesenovel POS precursors as such constitute intermediates of the processaccording to the invention.

Finally, the present invention relates to the use of theperoxide-comprising POSs as defined above as:

-   -   bleaching agent,    -   and/or disinfecting agent,    -   and/or cleaning agent,    -   and/or polymerization initiating agent,    -   and/or agent for epoxidation.

The peroxide-comprising POSs according to the invention are particularlysuitable as bleaching agent and more particularly still as agent forbleaching the teeth, due to their properties of selectivity with respectto teeth, of nontoxicity, of controlled reactivity of the Fpo peroxidefunctional groups (limitation of the production of free radicals), ofnontoxicity and of high effectiveness at a low dose.

The result of this is that another subject matter of the presentinvention is a dental composition (for example an oral composition), inparticular a dentifrice, characterized in that it comprisesperoxygenated POSs as defined above as bleaching agent.

Without this being limiting, a few details may be given which define,qualitatively and quantitatively, the dental composition according tothe invention by indicating that the latter comprises:

-   -   peroxygenated POSs in the proportion of 0.1 to 40% by weight,        preferably of 0.1 to 10% by weight, and more preferably still of        the order of 1 to 5% by weight;    -   polishing abrasives in a proportion of 5 to 40% by weight,        preferably of 5 to 35% by weight, it being possible for these        abrasives to be in particular silica, precipitated calcium        carbonate, magnesium carbonate, calcium phosphates, titanium,        zinc or tin oxides, talc, kaolin, abrasive particles comprising        a core of calcic material, preferably made of calcium carbonate,        and a shell of idrophobic product, preferably a fatty acid salt        and more preferably still a Na stearate;    -   one or more fluorinated compounds corresponding to a        concentration of the order of 0.005 to 2%, preferably 0.1 to 1%,        by weight of fluorine in said composition, it being possible for        these fluorinated compounds to be in particular salts of        monofluorophosphoric acid, in particular those of sodium,        potassium, lithium, calcium, aluminum and ammonium, or alkali        metal fluorides, in particular sodium fluoride;    -   optionally anionic, nonionic, amphoteric or zwitterionic        surface-active agents, in the proportion of approximately 0.1 to        10%, preferably of approximately 1 to 5%, of the weight of said        composition; mention may be made, by way of examples, of:        -   anionic surfactants, such as the sodium, magnesium, ammonium            or ethanolamine salts of            -   C₈-C₁₈ alkyl sulfates which can optionally comprise up                to 10 oxyethylene and or oxypropylene units (in                particular sodium lauryl sulfate)            -   C₈-C₁₈ alkyl sulfoacetates (in particular it, sodium                lauryl sulfoacetate)            -   C₈-C₁₈ alkyl sulfoacetates (in particular sodium dioctyl                sulfosuccinate)            -   C₈-C₁₈ alkyl sarcosinates (in particular sodium lauryl                sarcosinate)            -   C₈-C₁₈ alkyl phosphates which can optionally comprise up                to 10 oxyethylene and/or oxypropylene units            -   C₈-C₁₈ alkyl ether carboxylates comprising up to 10                oxyethylene and/or oxypropylene units            -   sulfated monoglycerides, and the like        -   nonionic surface-active agents, such as optionally            polyethoxylated fatty esters of sorbitan, ethoxylated fatty            acids, polyethylene glycol esters or polyether fatty            alcohols,        -   amphoteric surface-active agents, such as betaines or            sulfobetaines    -   optionally water in a proportion of approximately 0.1 to 50%,        preferably approximately 0.5 to 40%, of the weight of said        composition    -   optionally humectants, in the proportion of approximately 10 to        85%, preferably of 10 to 70%, of the weight of said composition,        humectants such as glycerol, sorbitol, polyethylene glycols,        lactilol, xylitol, and the like    -   optionally thickening agents, such as some silica used for this        purpose (Tixosil 43®, sold by Rhône-Poulenc, and the like), in a        proportion of 5 to 15% by weight, and/or polymers, used alone or        in combination, such as xanthan gum, guar gum, cellulose        derivatives (carboxymethylcellulose, hydroxyethylcellulose,        hydroxypropylcellulose, hydroxypropylmethylcellulose, and the        like), crosslinked polyacrylates, such as the Carbopol® products        distributed by Goodrich, alginates or carrageenans, or        Viscarin®, in a proportion of 0.1 to 5% by weight    -   optionally bactericidal, antimicrobial or antiplaque therapeutic        agents, such as zinc citrate, polyphosphates, guanidines,        bisbiguanides or other therapeutic cationic organic compound    -   optionally flavorings (essence of aniseed, of Chinese anise, of        mint, of juniper, cinnamon, clove or rose), sweeteners,        colorings (chlorophyll), preservatives, and the like.

The dentifrice composition forming the subject matter of the inventioncan be provided:

-   -   in various forms (pastes, gels or creams) prepared using        conventional processes,    -   and in various packagings (e.g. single- or twin-compartment).

The peroxide-comprising or peroxygenated POSs according to the inventionare not suitable only for the bleaching and cleaning of the teeth. Thisis because they have proved to be entirely effective as bleaching agentsin detergent compositions. Another subject matter of the presentinvention is thus detergent compositions comprising peroxygenated orperoxide-comprising POSs according to the invention as defined above asbleaching agents.

The present [lacuna] will be better understood with the help of thefollowing nonlimiting examples which also reveal some of the advantagesand the alternative embodiments of the invention. The preparation of theprecursor POSs of the peroxide-comprising POSs according to theinvention, the conversion by oxidation of these precursors toperoxide-comprising POSs and the evaluation of the latter in terms ofstability on storage and of bleaching power are presented in theseexamples.

EXAMPLES Example 1 Preparation of a -POS precursor (B) of a peroxide POSAccording to the Invention, this Precursor Being a PolydimethylsiloxaneComprising Trimethylsilyl Ends Carrying Functional Substituents of-propyl-oxy-benzoic Type

1.1. Synthesis of Allyloxybenzoic Acid

500 ml of distilled water, 5 1 of absolute ethanol and, gradually, 450.9g of potassium hydroxide (8.02 mol) are charged with vigorous stirring(240 rev/min) to a 10 1 reactor, under an argon head space, equippedwith a reflux condenser, a dropping funnel, a mechanical stirrer andthermometer probe. Once the potassium hydroxide has dissolved, 558.3 gof 4-hydroxybenzoic acid (4.04 mol) are charged. The reaction massbecomes cloudy and then becomes clear. Allyl bromide (489.0 g, i.e. 4.04mol) is then run in over 2 h at ambient temperature. After the allylbromide has been run in, the reaction medium is brought to 80° C. for 17hours.

After returning to ambient temperature, the reaction medium isneutralized by gradual addition over 1 h 30 of 1 l of 36% hydrochloricacid (11 mol). The reaction medium becomes milky and is filtered througha sintered glass No. 4 under vacuum. A white filtration cake is obtainedand is washed with water (250 ml).

The allyloxybenzoic acid which is found in the filtration cake ispurified by recrystallization. The filtration cake, 5 1 of absoluteethanol and 750 ml of distilled water are charged to the 10 1 reactor.The reaction mass is brought to reflux (80° C.) and distilled water isgradually added until a single clear phase is obtained, i.e. 1.75 1 ofdistilled water. The reaction mass is then decanted into a 10 1receptacle which is cooled with ice. The medium is allowed torecrystallize for 16 h and then filtration is carried out through asintered glass No. 4 under vacuum. The cake is washed with distilledwater (2 l, used over three occasions). Crystals are obtained and aredried under a 200 mmHg vacuum at 70° C. The yield is 35%.

1.2. Protection of Allyloxybenzoic Acid by a Trimethylsilyl Group

53.62 g of allyloxybenzoic acid, prepared in 1.1. (0.3 mol), areintroduced into a 250 ml three-necked flask, under an argon head space,equipped with a reflux condenser, a mechanical stirrer and a thermometerprobe, and 120.58 g of hexamethyldisilazane (0.75 mol) are run in over 1hour. The reaction medium is left in contact at 130° C. for 24 hours.After returning to ambient temperature, a solution of protectedallyloxybenzoic acid in solution of hexamethyldisilazane is obtained.

It is possible to purify the protected product by distillation undervacuum.

1.3. Hydrosilylation of Protected Allyloxybenzoic Acid

87.01 g of the solution of protected acid obtained in 1.2. (0.15 mol ofprotected acid) and 31.0 mg of platinum catalyst are introduced into a250 ml three-necked flask, under an argon head space, equipped with areflux condenser, a dropping funnel, a mechanical stirrer and athermometer probe. The reaction medium is brought to 80° C. and stirringis begun. 35.03 g of oil with structure A (0.13 mol of SiH functionalgroup) are then run into the reaction medium over 45 minutes. Thereaction medium is subsequently left in contact for 16 hours. Duringthis contact time, 7.5 mg of PtCl₂(PhCN)₂ are added.

2% by mass of carbon black is added at 85° C. and is left in contact for16 hours. After returning to ambient temperature, the reaction medium isfiltered through a board filter under pressure and then the reactionmass is returned to a single-necked round-bottomed flask equipped with amagnetic bar. The product is isolated by devolatilization at 120° C.under a vacuum of 1 mmHg.

The product thus isolated is deprotected by hydrolysis with distilledwater (200 ml), which is run onto the product to be deprotected over 1 h15, and heating at 90° C. for 16 hours. The medium becomes off white.The water is removed at 110° C. under a vacuum of 2 mmHg over 4 h 15.58.40 g of hydrosilylated oil of structure B are then obtained.

1.4. Purification of a Silicone Oil B Comprising Benzoic Acid FunctionalGroups

The starting material is an oil which is 92% pure on a mass basis with8% on a mass basis composed of ungrafted oligomers originating fromungrafted allyloxybenzoic acid or isomers of allyloxybenzoic acid.Several purification techniques are possible among the variouspurification techniques. The method employed here is fractionalprecipitation. It consists in dissolving the grafted oil obtained in1.3. in a hot alcohol. This alcohol can be more particularly methanol.The polymer is then precipitated by addition of water of basic pH. Theoperation is repeated a further time. The third operation consists indissolving the silicone polymer under hot conditions in methanol and inthen adding water at acidic pH. The polymer thus purified is heated at115° C. under a vacuum of 20 mmHg in order to remove the residual wateror alcohol. The product is finally placed in an oven at 100° C. atatmospheric pressure. A polymer with a purity of greater than 95% byweight is obtained.

Example 2 Preparation of a -POS Precursor (C) of a Peroxide POSAccording to the Invention, this Precursor Being a PolydimethylsiloxaneComprising Trimethylsilyl Ends Carrying Functional Substituents of-propyl-succinic anhydride Type

Synthesis of the Silicone Oil C Comprising Succinic Anhydride Units

119.53 g of allylsuccinic anhydride, with a purity of more than 99 mol %(0.85 mol), and 44.2 mg of Karstedt platinum, comprising 10% by mass ofplatinum, are introduced into a 500 ml three-necked flask equipped witha mechanical stirrer, a reflux condenser, a dropping funnel and atemperature probe while flushing with argon. The reaction medium isbrought to 90° C. with stirring and then 175.53 g of oil with structureA (0.66 mol of SiH functional group) are run in over 1 h 25. Thereaction medium is left in contact at 90° C. with stirring for 4 hours.The reaction medium is subsequently treated with 2% by weight of carbonblack at 70° C. for 4 hours. After returning to ambient temperature, thereaction medium is filtered through a board filter under nitrogenpressure. After having placed the reaction medium in a single-neckedround-bottomed flask equipped with a magnetic bar, the grafted siliconepolymer is isolated by devolatilizing the excess oligomer by heating at180° C. under a vacuum of 2 mmHg. A silicone oil with structure C andwith a purity equal to 94% by weight is obtained.

In order to purify this product to a purity of more than 99% by weight,the product was devolatilized using a diffusion pump under a vacuum of10⁻³ mmHg while heating the polymer from 120 to 160° C. for 6 hours. Asilicone polymer grafted with propylsuccinic anhydride is then obtainedwith a purity of greater than 99% by weight. Infrared analysis showsthat the anhydride is not opened during the treatments described in theexamples.

Example 3 Preparation of a -POS Precursor (E) of a Peroxide POSAccording to the Invention, this Precursor Being a PolydimethylsiloxaneComprising Trimethylsilyl Ends Carrying Functional Substituents of-propyl-succinimide-benzoic Type

3.1. Preparation of Silicone Comprising an Amine Functional Group byCoequilibration

50 g of aminopropyldimethoxymethylsilane (0.3 mol) are introduced into athree-necked flask, under an argon head space, equipped with adevolatilization system, a mechanical stirrer, a dropping funnel and atemperature probe, and an amount of water of 27.6 g (1.5 mol) is addedover 1 hour. The system is brought to 110° C. and is devolatilized under11 mmHg in order to collect the amount of methanol of 19.2 g.

After returning to [lacuna] temperature and having replaced thedistillation system by a reflux condenser, 30.5 g ofoctamethyltetrasiloxane (0.1 mol, i.e. 10% excess), 34.3 g of a shortsilicone oil with 6 silicons of formula M₂D₄ and 5.3 g of potassiumsiliconate comprising 15% by weight of potassium hydroxide (80 ppm), inaddition to 35.1 g of hydrolyzed silane obtained above, are introduced.After heating at 130° C. for 6 hours while stripping with nitrogen, thereaction mixture is neutralized by addition of 12.3 g of a solution ofsilicated ester of phosphoric acid comprising 9% by mass of phosphoricacid. Following the neutralization, the medium is left in contact for 30minutes at 80° C. and then devolatilization is carried out under 2 mmHgat 170° C. 113.5 g of silicone oil with structure D are obtained.

3.2. Formation of a Silicone E Comprising Acid and Imide FunctionalGroups

28.8 g of trimellic anhydride (0.15 mol) and 75 g of toluene are chargedto a three-necked round-bottomed flask, under an argon head space,equipped with a reflux condenser, a mechanical stirrer, a droppingfunnel, a thermometer probe and a Dien & Stark apparatus, and 50.0 g ofsilicone oil comprising an amine functional group with structure D (0.15mol of amine functional group) are run in over 1 hour. The reactionmixture is left in contact at ambient temperature for 1 hour and thenthe reaction mixture is brought to reflux for 5 hours; during the time,removal of the water is monitored. After returning to ambienttemperature, the reaction mixture is filtered through a board filterunder pressure. After having placed the reaction mixture in asingle-necked round-bottomed flask equipped with a magnetic bar, thesolvent is devolatilized by heating at 110° C. under a vacuum of 10mmHg. A polymer with structure E is obtained with a purity of 95% byweight.

Example 4 Preparation of a -POS Precursor (F) of a Peroxide-comprisingPOS According to the Invention, this Precursor Being aPolydimethylsiloxane Comprising Trimethylsilyl Ends Carrying FunctionalSubstituents of Aminoethylaminopropyl (H₂N—(CH₂)₂—NH—(CH₂)₃—) Type

Example 3 is repeated apart from the difference that theaminopropyldimethoxymethylsilane employed in part 3.1. is replaced foraminoethylaminopropyldimethoxymethylsilane and, ultimately, a POSprecursor or silicone oil F is obtained:

-   -   [lacuna]

Example 5 Preparation of a Peroxide-comprising POS in which the Fpo(—O—O—) Functional Groups of the E Substituents Are Included inPercarboxylic Acid Residues

from the Pos Precursor According to Example 2 (Pendant AnhydrideResidues)

5.1. Test

The following operations are carried out in a weighing tube:

-   -   250 mg of silicone oil C of Example 2, i.e. 0.615 mmol of        anhydride functional groups (4 functional groups per polymer),        are weighed out,    -   0.5 ml of ethyl acetate (AcOEt) is added,    -   45 mg of 70% hydrogen peroxide, i.e. 0.926 mmol (1.5 equivalents        excess with respect to the stoichiometry, which is 1 H₂O₂ per        anhydride), are weighed out,    -   1 drop of KOH (1N) is introduced,    -   a small magnetic bar is added,    -   the mixture is stirred at ambient temperature for 1 hour.        5.2. Treatment    -   3 ml of AcOEt are added    -   the mixture is transferred into a small 50 ml separating funnel    -   3 ml of deionized water comprising 100 g/l of ammonium sulfate        are added    -   the mixture is agitated and allowed to separate by settling, and        the lower aqueous phase is removed    -   the operation is restarted a further 2 occasions    -   the organic phase is recovered in a 50 ml beaker    -   1 g of anhydrous MgSO₄ is added    -   the solution is transferred into a tared 50 ml round-bottomed        flask and the separating funnel and MgSO₄ are rinsed twice with        1 ml of AcOEt    -   the solution is evaporated to dryness on a rotary evaporator,        bath at a maximum of 35°    -   the residue is evaporated for a few minutes under pump vacuum        under cold conditions (ambient temperature)    -   the product obtained is weighed.        5.3. Quantitative Determination of Peroxides in the        Peroxide-comprising Silicone Oil

Apparatus: Metrohm Dosimat 665

5.3.1. Procedure

The following operations are carried out in a 50 ml Erlenmeyer flask:

-   -   approximately 250 mg of peroxide-comprising oil are weighed out    -   the following are added:        -   20 ml of 80/20 acetic acid/H₂O mixture and dissolution is            allowed to take place        -   or, better still, 20 ml of pure acetic acid, dissolution is            allowed to take place and then a small amount of water is            added    -   1 spatula (1 g) of NaHCO₃ is added (inerting by CO₂)    -   1 spatula (1 g) of potassium iodide is added    -   the flask is stoppered and placed in darkness for a minimum of        20 minutes.

The contents of the Erlenmeyer flask are transferred into a 150 mlbeaker (tall form):

-   -   rinsing is carried out with 50 ml of distilled water    -   acetone is added (maintenance of the solubility and antifoaming)    -   a magnetic bar is added and the iodine released is        quantitatively determined with a 0.1 N sodium thiosulfate        solution.        5.3.2. Calculations

Number of mmol of H₂O₂=V ml×CO3×CO2/COO×CO1 Weight % of H₂O₂=Number ofmillimoles quantitatively determined×34/1000

1 equivalent H₂O₂=1 equivalent R—CO—O—OH

5.3.3. Expression of the Results: Weight % as H₂O₂ Equivalent

Given that the -POS precursor (oil C) prepared in Example 2 comprisesthe E substituents each carrying an anhydride and that the reaction isregarded as total (oxidation yield=100%), then, for one mol of oil (C),4 mol of H₂O₂ are reacted, i.e. as % by weight: 1 mol of oil (C)=1628 g,for 4 mol of H₂O₂=136 g, i.e. 8.35 weight % of H₂O₂.

5.3.4. Result

The content of peracid in the oxidized oil C is 6.2%, i.e. an oxidationof 6.2/8.35×100=74%.

Example 6 Preparation of a Peroxide-comprising POS in which the Fpo(—O—O—) Functional Groups of the E Substituents are Included inPercarboxylic Acid Residues

from the POS Precursor According to Example 2 (Pendant AnhydrideResidues)

The following are charged to a 100 ml round-bottomed flask:

-   -   15 g of oil C of Example 2 (36.9 mmol of anhydride)    -   30 g of ethyl acetate    -   2.7 g of 0 70% hydrogen peroxide (55.6 mmol (×1.5))    -   0.6 ml of N KOH (0.6 mmol).

A magnetic bar is added and stirring is begun. There is an immediateexotherm and the temperature reaches 31° C.

A crystallizing dish of cold water is installed to bring the temperatureto ambient temperature.

The mixture is maintained for 1 hour.

The mixture is decanted into a 100 ml separating funnel and theround-bottomed flask is rinsed twice with 10 ml of AcOEt.

The organic phase is washed 8 times with 20 ml of deionized watercomprising 100 g/l of ammonium sulfate: the disappearance of thehydrogen peroxide in the aqueous phases is monitored by an indicatorpaper for peroxides.

The organic phase is dried over anhydrous MgSO₄.

The organic phase is filtered through a sintered glass filter.

The organic phase is decanted into a 100 ml round-bottomed flask and theseparating funnel and the sintered glass filter are rinsed. The organicphase is evaporated to dryness on a rotary evaporator, bath at a maximumof 35°.

The residue is dried under pump vacuum for 3 hours at ambienttemperature.

-   -   Weight obtained: 15.4 g    -   Content of peracids: 5.46% (expressed as H₂O₂)    -   Oxidation: 65%

Example 7 Study of the Stability on Storage of Peroxide-comprising POSsAccording to the Invention

The POS used is prepared according to the methodology given in Example6.

The product is stored dried at 5° C. and 25° C.

Samples are withdrawn over time and the peroxides therein arequantitatively determined as describes above in 5.3.

7.1. Storage at 5° C. from 0 to 30 Days

The results are given by Table 1 below.

TABLE 1 Duration (d) % Peracids % Oxidation 0 5.72 100.0 2 5.48 95.8 65.08 88.8 13 3.82 66.8 22 2.90 50.7 30 1.70 30.07.2. Storage at 5° C., 0, 11 and 22 Days

The results are given by Table 2 below.

TABLE 2 Duration days % Peracids 5° C. % Oxidation 5° C. 0 5.46 100.0 114.24 74.1 22 2.85 49.8

Example 8 Preparation of a Peroxide-comprising POS in which the Fpo(—O—O—) Functional Groups of the E Substituents are Included inPercarboxylic Acid Residues

from the POS Precursor According to Example 2 (Pendant AnhydrideResidues)

Example 5 is repeated apart from the difference that KOH is not used.

Results

-   -   Content as H₂O₂ equivalent=0.59%    -   Oxidation: 7%

Example 9 Preparation of a Peroxide-comprising POS in which the Fpo(—O—O—) Functional Groups of the E Substituents Are Included inPercarboxylic Acid Residues

from the POS Precursor According to Example 2 (Pendant AnhydrideResidues)

Example 6 is repeated apart from the difference that the drop of KOH isreplaced by a drop of H₃PO₄ (85% in water)

Results:

-   -   Content as H₂O₂ equivalent=1.03%    -   Oxidation: 12%

Example 10 Preparation of a Peroxide-comprising POS in which the Fpo(—O—O—) Functional Groups of the E Substituents Are Included inPercarboxylic Acid Residues

from the POS Precursor According to Example 1 (Pendant Benzoic Residues)

10.1. Test

The following operations are carried out in a weighing tube:

-   -   250 mg of silicone oil B of Example 1, i.e. 0.578 mmol of acid        functional groups (4 functional groups per polymer), are weighed        out    -   0.5 ml of ethyl acetate (AcOEt) is added    -   84 mg of 70% hydrogen peroxide, i.e. 1.729 mmol (3 equivalents        excess with respect to the stoichiometry, which is 1 H₂O₂ per        acid), are weighed out    -   1 drop of H₂SO₄ (95% in water) [lacuna]    -   a small magnetic bar is added    -   the mixture is stirred at ambient temperature for 2 hours in the        presence of an excess of anhydrous MgSO₄ (>100 mg).        10.2. Treatment    -   3 ml of AcOEt are added    -   the mixture is transferred into a small 50 ml separating funnel    -   3 ml of deionized water comprising 100 g/l of ammonium sulfate        are added    -   the mixture is agitated and allowed to separate by settling, and        the lower aqueous phase is removed    -   the operation is restarted a further 2 occasions    -   the organic phase is recovered in a 50 ml beaker    -   1 g of anhydrous MgSO₄ is added    -   the solution is transferred into a tared 50 ml round-bottomed        flask and the separating funnel and MgSO₄ are rinsed twice with        1 ml of AcOEt    -   the solution is evaporated to dryness on a rotary evaporator,        bath at a maximum of 35°    -   the residue is evaporated for a few minutes under pump vacuum        under cold conditions (ambient temperature)    -   the product obtained is weighed.        10.3. Result    -   Content of peracid: 0.66%    -   Oxidation: 9%

Example 11 Evaluation of the Bleaching Power of the Peroxide-comprisingPOS of Example 6

11.1. Method in Development for Determining the Bleaching Power withRespect to Hydroxyapatite HAP Powder

11.1.1. Principle

-   -   Measurement of the bleaching power of oxidizing compounds with        respect to a hydroxyapatite HAP powder contaminated beforehand        by a hot tea solution.    -   Bleaching power quantified by calorimetric measurements carried        out on a Minolta CR-241 device.        11.1.2. Equipment        A—Small Items    -   Filter paper, “rapid filtrations” No. 41 from Whatman, for the        filtration of the tea solution and for the recovery of the        contaminated powder    -   Filter paper, GF/C, diameter of 47 mm, from Whatman, used for        the recovery of the bleached powder    -   Büchner funnel (diameter of 100 or 160 mm), 2 l vacuum filter        flask, vacuum pump or filter pump with a differential manometer,        and rubber seals    -   Pots made of crystal polystyrene (transparent), capacity of        approximately 40 ml        B—Devices    -   Minolta CR-241 colorimeter    -   Promax 2020 to-and-fro stirrer    -   Oven (50 to 100° C.)        C—Products    -   Deionized water    -   Lipton Yellow Tea, Grade No. 1    -   Bio-Rad hydroxyapatite HAP powder    -   Solution or oxidizing agent        11.1.3. Procedure        A—Contamination of the HAP Powder

a—Measurement of the initial whiteness of the powder

A measurement of the initial whiteness of the HAP powder is carried out.It is carried out on a Minolta CR-241 device. Three measurements aremade in order to obtain a mean value of Lo, ao, bo.

b—Brewing of the tea and filtration

500 ml of deionized water and 10 cut tea bags are introduced into a 1000 ml beaker (C=˜40 g/l) and brought to ˜80° C. with mechanicalstirring (200 rev/min) for 90 minutes.

The stirring and the heating are halted. Once the medium has cooled toapproximately 40° C. (time necessary=˜90 min), it is filtered undervacuum.

The filtrate (=contaminating tea solution) is recovered. Its volume isreadjusted to 500 ml with deionized water.

c—The contamination

7.5 g of HAP powder are introduced into the tea solution.

The combined mixture is again brought to ˜80° C. with stirring for 45minutes.

The heating and the stirring are halted and the medium is cooled by thesurrounding air (to ˜40° C.) before being filtered under vacuum.

The powder is washed with three times 20 ml of hot deionized water untilthe filtrate is colorless.

The filter and the powder are placed in the oven [T=50-100° C.] untilthe water has completely evaporated.

The powder, recovered in the form of agglomerates, is ground using apestle and mortar.

Its new whiteness is measured (Ls, as, bs) with a Minolta CR-241.

B—Bleaching of the Contaminated HAP Powder

6.5 g of oxidizing solution (comprising the equivalent of 0.3% of H₂O₂)and 50 mg of contaminated HAP powder are decanted into a flask made ofcrystal polystyrene with a capacity of approximately 40 ml.

The combined mixture is placed on the Promax 2020 to-and-fro stirrer forthe desired time (15 min, 30 min. 1 h, 2 h, and the like) at the rate of250 to-and-fro movements.

The medium is subsequently diluted by addition of 20 ml of ethanolbefore being filtered.

The powder is washed with three times 30 ml of ethanol.

The combined filter+bleached powder is dried in the open air under ahood.

The new whiteness of the bleached powder can be measured (Lc) and thebleaching power of the oxidizing solution can be calculated.

11.1.4. Calculations

The calculation of the bleaching power of the oxidizing compound is madefrom the value L given by the calorimeter obtained after the varioustreatments of the HAP powder.

-   L* represents the lightness of the sample, its values ranging    between 0 and 100.

The various values are thus defined:

-   Lo, initial lightness before contamination-   Ls, lightness after contamination-   Lc, lightness after bleaching.

The bleaching power is calculated as follows: Bleaching power:Bleaching  power:$\quad{{Pb} = {\frac{{Lc} - {Ls}}{{Lo} - {Ls}} \times 100}}$11.2. Measurement of the Whiteness Lc Obtained in the Test Described in11.1. Above with the Peroxide-comprising POS of Example 611.2.1. The Bleaching of the HAP Powder According to Part 11.1.3.B AboveIs Carried Out as Follows

6.5 g of oxidizing preparation comprising 300 mg of peroxide-comprisingPOS according to Example 6 dispersed in 6.2 g of water inverted bymanual agitation and 50 mg of contaminated HAP-powder are decanted intoa flask made of crystal polystyrene with a capacity of 40 mg.

The procedure is subsequently as indicated in part 11.1.3.B.

11.2.2. Results

TABLE 3 Time Lc with water Lc with peroxide- (min) control Pb*comprising POS Pb* 0 50 0 50 0 15 49 0 69 45 60 49 0 69 45 120 49 0 7048

${*{Pb}} = {\frac{{Lc} - {Ls}}{{Lo} - {Ls}} \times 100}$Ls = 50  and  Lo = 92

1. Polyorganosiloxanes (POSs) comprising siloxane units having thefollowing formulaR¹ ₃SIO—[SiR² ₂O]_(m)—[Sir²EO]_(n)—[Sir²GO]₀—SiR³ ₃  (II) wherein E,which is identical or different, is a monovalent functional substituentselected from the group consisting of (cyclo)aliphatic hydrocarbonaceousgroups, aromatic, hydrocarbonaceous groups and heterocyclichydrocarbonaceous groups, carrying one or more functional group Fpo ofthe following formula,

wherein X is hydrogen, a halogen atom, or a cation forming a salt withthe acyl peroxide anions, G, which is identical or different, is afunctional substituent comprising one or more Fpo-stabilizing functionalgroup Fstab, which are identical to or different from one another,capable of bonding via weak bonds with the Fpo functional group, theconcentration {Fpo} of Fpo functional groups, expressed by the ratio${\{ {Fpo} \} = \frac{{Fpo}\quad{number}}{{Total}\quad{number}\quad{of}\quad{silicon}\quad{atoms}\quad{in}\quad{the}\quad{POS}}},$ is greater than 0, and the concentration {T and/or Q} as mol %, ofunits selected from the group consisting of T units and Q units, is from0 to 20, T units being defined as siloxane units wherein a+b+c=1, R¹ andR³, which are identical or different, are hydrogen, a hydroxyl or amonovalent a hydrocarbonaceous group, R², which is identical ordifferent, is hydrogen, hydroxyl, or a monovalent a hydrocarbonaceousgroup, wherein 3≦m+n+o≦50, 1≦m≦100, 1≦n≦10, and 1≦o≦10. 2.Polyorganosiloxanes according to claim 1, whereat least one Esubstituent further comprises one or more Fpo-stabilizing functionalgroup Fstab, which are identical to or different from one another, andcapable of bonding via weak bonds with the Fpo functional group. 3.Polyorganosiloxanes according to claim 1, wherein 0.1≦{Fpo} ≦0.6. 4.Polyorganosiloxanes according to claim 1, wherein X is an elements fromcolumns Ia and IIA of the Periodic Table.
 5. Polyorganosiloxanesaccording to claim 1, wherein Fstab generates weak bonds (hydrogenbonds) with Fpo functional groups, and is selected from the groupconsisting of: functional units comprising nitrogen, oxygen, fluorine,sulfur or phosphorus, cationic units, chelating units comprising one ormore ether or amine functional group, phosphonate chelating units, andsulfonate chelating units.
 6. Polyorganosiloxanes according to claim 1,wherein Fstab generates weak bonds (hydrogen bonds) with Fpo functionalgroups, and is selected from the group consisting of carboxylic units,carboxylate units, amide units, imide units, sulfonamide units, hydroxylunits, alkoxy units, amine units, organofluorinated units, andquaternary ammoniums units.
 7. Polyorganosiloxanes according to claim 1,wherein 5≦m+n+o≦20, 1≦m≦10, 2≦n≦4, and 2≦o≦4.
 8. Polyorganosiloxanesaccording to claim 1, wherein: R¹ and R³ C₁-C₃ alkyl, R² is a C1-C3alkyl, and E carries Fpo and Fstab functional groups. 9.Polyorganosiloxanes according to claim 8, wherein R¹, R² and R³ aremethyl groups.